<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>浮动练习</title>
  <style>

  </style>
</head>
<body>
  <div class="f1">
    <div class="left"></div>
    <div class="right"></div>
  </div>
  <div class="f2">
    <div class="left"></div>
    <div class="card"></div>
    <div class="card"></div>
    <div class="card"></div>
  </div>
</body>
</html>